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Mixing Pyrocat-HD

Dan Henderson

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I am making up my first batch of Pyrocat HD from raw chemicals. As I have experienced in the past with other developers, I am having trouble getting the phenidone to dissolve. I am breaking it up as finely as I can in a mortar and pestle, and adding it as slowly as possible, but the small, undissolved chunks remain. Is there a better way to dissolve the phenidone for this and other developers, and if the small chunks remain, what will this do to the developer?

Thanks for any and all help,
Dan
 
Dan,

I've only mixed up one batch of Pyrocat-HD (last year and still working) using warmed water. If I remember correctly the Phenidone went into solution surprisingly easily consider the warnings I'd read, however, the Potassium Carbonate 'B' solution took around 45 minutes to mix the saturated solution, but perhaps I was being overly cautious.

Tom
 
You might try dissolving the Phenidone in a small amount of 90% Isopropyl alcohol before you add it to the other ingredients. I don't understand why you need a mortar and pestle to break up the Phenidone, mine has always been a fluffy powder. Is it old?
 
I have worked with Pyrocat HD for just over a year now. My best luck with dissolving Phenidone with with a small amount of alcohol. But, then again it has not been much of a problem. I use a magnetic stirrer that has done a great job.
 
+1 on the stirrer, and patience.
 
thanks for the info, guys. I spoke a little too soon, with, as Jim suggested, a little patience and letting my stirrer to it's work, the phenidone did finally dissolve. As to Richard's question, no, the phenidone is new and is not clumped like potassium bromide does. It does, however, stick together in small clumps that I though might dissolve more quickly if I broke them up in a mortar. Which really did not seem to make all that much difference; maybe I should have left it alone!

I wondered about dissolving the phenidone in alcohol, but worry that it might affect properties of the developer unless one of the experts here says otherwise.
Thanks again,
Dan
 
Some past advice from Sandy about the use of alcohol:

(there was a url link here which no longer exists)

and my favorite: (YMMY...)

(there was a url link here which no longer exists)
 
Last edited by a moderator:
There is another way. The sulfite ion, in the form of the metabisulfite, serves two purposes in general, but it mostly ensures the synergism between catechol and phenidone in Pyrocat HD. A small amount of ascorbic acid may be used in place of the metabisulfite. Now, the catechol, phenidone and ascorbic acid are all soluble in propylene glycol. Use it as solvent in place of water in the A solution. Somewhere in APUG you will find specific instructions for this recipe.
 

Pat is right about mixing in glycol.

I am attaching a word file that has mixing directions for most of the pyrocats. Just to clarify, I call Pyrocat-HD that is mixed in glycol and uses ascorbic in place of metabisulfite Pyrocat-HDC, the C simply denoting vitamin C or ascorbic acid. It works almost identically to the regular version but is somewhat easier to mix because ascorbic goes into solution in glycol easier than metabisulfite.

Sandy King
 

Attachments

  • Mixing Pyrocats.txt
    7.1 KB · Views: 470
I could easily convert this document to HTML and post it on the web.

That way, people would be able to find it readily via a search engine like Google. I'm not sure if search engines visit this forum.

Alternately, you could put it on Unblinking Eye or somewhere else more in the "public domain". I'm not trying to draw traffic to my site, just be of help. I have nothing to sell anyhow

 
Search engines index this forum very quickly indeed, often within minutes.

Having just made up a batch of Pyrocat, and ID-78 (A PQ Warmtone dev) I have to say I've always found Phenidone dissolves very easily, I've never had even a slight problem in 30+ years.

There's something wrong with your Phenidone if you have to break it up in a pestle & mortar, it keeps for decades with no deterioration but should be a light fluffy powder. Sounds like poor storage and damp Phenidone.

Ian
 
Search engines index this forum very quickly indeed, often within minutes.

Excellent.

Even so, it would be nice to have a simple way to find information on this subject, without having to traverse a long series of results.
 
An excellent way to search APUG (or any other group) is to google it specifically, such as:
phenidone solubility site:apug.org

saves heaps of time and beats the resident search engine hollow.
Murray



Kenneth Lee said:
Search engines index this forum very quickly indeed, often within minutes.

Excellent.

Even so, it would be nice to have a simple way to find information on this subject, without having to traverse a long series of results.
Click to expand...
 

Please feel free to convert the document to HTML and post it on the web if you like. I have no objection to this.

One day I will update the article at Unblinking Eye on pyro staining developers. Unfortunately I have several other writing projects before this one in the queue and it will be a while before I get to the update.

Sandy
 
The txt file seems to have two errors though:


Instead of 20%, a 15% solution would be needed if 5x the amount is needed with a lower concentration solution. The "dichromate" should also be replaced with "carbonate"
 
Kenneth Lee said:
Search engines index this forum very quickly indeed, often within minutes.

Excellent.

Even so, it would be nice to have a simple way to find information on this subject, without having to traverse a long series of results.
Click to expand...

Ken,
A couple of years back I registered the domain pyrocat-hd.com thinking that in some point could be convenient to have a "official" source for the information related to the Pyrocat-HD family of developers. I mentioned it more than once to Sandy in the past but I guess is too busy.
I don't know if this is the right moment but you (and the rest of the users) are more than welcome to come up with design ideas for the page/site.
Of course, I think Sandy should have full control of the content.
Armando.
 

Excellent. Thanks. Shall I incorporate the corrections offerd by Annon Ymous ?
 

I'd be happy to help out in any way I can - but I leave it to Sandy to consider.

That particular domain name may now be a bit restrictive, given the variations which exist today. It could be remedied with a slightly different name.

That said, I think there's a "synergistic" value to hosting such articles here on APUG, or at Unblinking Eye - where there are already so many related articles and interested members.

In the time that Sandy might spend on such a project, he could simply update and expand the existing articles.
 
Philippe Grunchec said:
Would be great, Sandy!
In particular, i'd like to know what you recommend for alt processes in terms of dilution, 1+2+100 or 2+2+100...
Click to expand...

If you need to develop the negative to a high contrast for alternative processes I would recommend a 2+1+100 dilution, or even 3+2+100. The higher percentage of A solution, which is the reducer, will tend to minimize B+F or general stain.

Sandy King
 

Armando,

Unfortunately I am getting to that stage of life where there is only so much room in the mind for new concepts and ideas. I do now recall you mentioning this to me at least once in the past, but indeed it had slipped my mind. My technical knowledge of web sites is very limited but if you want to go ahead and set up a site on Pyrocat-HD that is a repository of information about the pyrocats, either by yourself or with help from someone else, that would be great as far as I am concerned. I will of course be willing to review any information that is proposed for the site.

I am sure that a FAQ on Pyrocat could be a very interesting part of such a site.


Sandy
 
Sandy,
I'll be in touch with Ken to get the site up and running. Don't worry about the technical part, text format is fine. Please, forward an updated version of the FAQ to Ken as soon as you get a chance. His experience with pyrocat-hd will be essential in designing the web site.
Armando
 

I will have to create a FAQ. Over the years I have personally answered hundreds, perhaps thousands, of personal messages about Pyrocat, and can not now locate a single one of them!

Sandy King
 
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